mirror of https://github.com/borgbackup/borg.git
68 lines
2.2 KiB
Cython
68 lines
2.2 KiB
Cython
# -*- coding: utf-8 -*-
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API_VERSION = '1.1_01'
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from libc.stdlib cimport free
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cdef extern from "_chunker.c":
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ctypedef int uint32_t
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ctypedef struct _Chunker "Chunker":
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pass
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_Chunker *chunker_init(int window_size, int chunk_mask, int min_size, int max_size, uint32_t seed)
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void chunker_set_fd(_Chunker *chunker, object f, int fd)
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void chunker_free(_Chunker *chunker)
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object chunker_process(_Chunker *chunker)
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uint32_t *buzhash_init_table(uint32_t seed)
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uint32_t c_buzhash "buzhash"(unsigned char *data, size_t len, uint32_t *h)
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uint32_t c_buzhash_update "buzhash_update"(uint32_t sum, unsigned char remove, unsigned char add, size_t len, uint32_t *h)
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cdef class Chunker:
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cdef _Chunker *chunker
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def __cinit__(self, int seed, int chunk_min_exp, int chunk_max_exp, int hash_mask_bits, int hash_window_size):
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min_size = 1 << chunk_min_exp
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max_size = 1 << chunk_max_exp
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# see chunker_process, first while loop condition, first term must be able to get True:
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assert hash_window_size + min_size + 1 <= max_size, "too small max_size"
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hash_mask = (1 << hash_mask_bits) - 1
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self.chunker = chunker_init(hash_window_size, hash_mask, min_size, max_size, seed & 0xffffffff)
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def chunkify(self, fd, fh=-1):
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"""
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Cut a file into chunks.
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:param fd: Python file object
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:param fh: OS-level file handle (if available),
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defaults to -1 which means not to use OS-level fd.
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"""
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chunker_set_fd(self.chunker, fd, fh)
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return self
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def __dealloc__(self):
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if self.chunker:
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chunker_free(self.chunker)
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def __iter__(self):
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return self
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def __next__(self):
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return chunker_process(self.chunker)
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def buzhash(unsigned char *data, unsigned long seed):
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cdef uint32_t *table
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cdef uint32_t sum
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table = buzhash_init_table(seed & 0xffffffff)
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sum = c_buzhash(data, len(data), table)
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free(table)
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return sum
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def buzhash_update(uint32_t sum, unsigned char remove, unsigned char add, size_t len, unsigned long seed):
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cdef uint32_t *table
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table = buzhash_init_table(seed & 0xffffffff)
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sum = c_buzhash_update(sum, remove, add, len, table)
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free(table)
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return sum
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